The pharmaceutical industry has expended vast technical and financial resources to develop novel therapeutic agents. Yet, the failure rate (more than 90%) for lead compounds remains persistently high. Often, lead drug compounds that meet expectations in preclinical models, such as inbred animal models, or a small number of cell lines, are toxic or ineffective when administered to a human clinical trial patient population. A fundamental deficiency in most current drug development efforts is that they do not evaluate candidate drug efficacy and toxicity in the context of the extreme genetic diversity of the human patient population. In other words, in the present drug development paradigm, drug efficacy and toxicity are not tested on many, if not most, of the relevant genotype/phenotype combinations present in the human population. Indeed, even after successful trials in a relatively small human clinical trial population, unexpected adverse effects can be revealed once these drugs are administered to a broader human patient population.